coils for pulse motor

[kajunkreations]

Hey guys, I am new here, and Ive been playing around with a few pulse motors for a few months now. I have been inspired by all of you, and you guys do some really good work. Anyway I have a question about coils size vs magnet size.

What size coil would you use to repel a 1" dia X 3/4" thick neo mag using 12 volts.

core size? wire size? impedance?
Any info would be greatly appreciated.

Thanks,
Nolan Menne

[kajunkreations]

47 veiws and no help. come on guys hepl me out here

[Joit]

Well, Hi and then.

It depends, what you are up to, and you may specify yourself more.
IE. about, how much Energy you wanna chase through, how much do you want it to repel, means, high torque or just some.

Most, i think make them with a rough estimation, since we dont build Rockets and need rocket Science for it.
But generally its like this, Thinner Wire, lower Consumption more Resistance, and the Windings give the Strenght.
Thicker Wire, more Consumption, close to Shorts sometimes, more Space what you need, and low resistance Coils.
For the Core, i saw, that there, where the Wire is, the repelling happens, lesser with a thick Core. But a Core still amplify the Magnetfield a bit, and therefor you have a bit lesser Consumption.
Usual you can build with #18 or #24 Wires neat Coils, for the Core, it may depends, how big you wanna make the Coil.
Here is a List from the Wires, scroll down for the table. American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies and look what you wanna chase through.
Anything above the Specification from the Wire will may cause heat,
even, when its at Pulse System some more variable, but it still depends on the Duty Cycle from the Pulse.

[dR-Green]

Welcome

I would start with a core that's about the same diameter as the magnet is wide, so in other words the magnet passes over the whole core, not only a part of it. I make my coils with 20mm diameter PVC conduit for the core, with 20mm diameter disk or 20mm wide x 8mm long block magnets on the rotor.

With the block magnets the 20mm width covers the entire core in one direction, and in the direction of rotation it covers 8mm of the core.

[Joit]

dr-green,
That what i thought also about the core, that the same size should be better.
But after playing around with certain Coils, i saw, that the strongest Moment is, when the Magnet passes the Wires. Middle from the Magnet to the middle of the one Side from the wire (Because of the big Core).
The Reason for that is, that you still have drag from the Iron or whatever you use for the Core, this reduces the Force from the Electro Magnetic Field and make it weaker. Also at the Core, the Magnetfield seems to turn into the opposite, you can see this also at a big Ring Magnet.
And the Drag appears even when you turn the Coils on when the Magnet directly passing the Core.
Both are Things, what shows no advantage with an equal or to big Cores.
To small has the disadvantage, that it may has no or less effect.

[kajunkreations]

thanks guys, I am looking for the most repulsion i can have. I am using TIP3055's to drive them. I have found that 2.5 to 3.0 ohms works good without to much heat.
The coils I currently run are 22 ga with a 3/8 ferrite core. I dont know how many turns there are , but the are wound to 3.0 ohms. They do build up a little heat after a half an hour or so, getting to 155 degrees.
Im thinking I need to go up in wire size to prevent this form happening. My device is a 9 coil pair MULLER style motor with all coils driving, I am only looking for torque. So I would appreciate any info from you guys.